It has been known for several years that organic semiconductors can be modified extensively in terms of their electrical conductivity by doping (electrical doping). Organic semiconductive matrix materials of such kind can be constructed either from compounds with relatively good electron donor properties or from compounds with relatively good electron acceptor properties. Strong electron acceptors such as tetracyanoquino-dimethane (TCNQ) or 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4TCNQ) have become known to be effective in doping electron donor materials (HT) (U.S. Pat. No. 7,074,500). By electron transfer processes, these substances generate “holes” in electron donor type base materials (hole transporter materials), and the conductivity of the base material is modified to a greater or lesser degree depending on the number and mobility of these holes. Known examples of matrix materials with hole transporter properties include N,N′-perarylated benzidines (TPD) or N,N′,N″-perarylated starburst compounds such as the substance TDATA, or also certain metal phthalocyanines, such as in particular zinc phthalocyanine ZnPc.
However, the previously described compounds have disadvantages for a technical use in the production of doped semiconductive organic layers or of corresponding electronic components with such doped layers since the manufacturing processes in large-scale production plants or those on a technical scale cannot always be controlled with sufficient precision, which results in high control- and regulating expense within the processes for achieving a desired product quality or in undesired tolerances of the products. Furthermore, there are disadvantages in the use of previously known organic acceptors with regard to electronic components such as light-emitting diodes (OLEDs), field effect transistors (FET) or solar cells since the cited production difficulties in the handling of the doping agents can lead to undesired irregularities in the electronic components or undesired ageing effects of the electronic components. However, it should be noted at the same time that the doping agents to be used have extremely high electron affinities (reduction potential) and other properties suitable for the application case since for example the doping agents also co-determine the conductivity or other electrical properties of the organic semiconductive layer under given conditions. The energetic positions of the HOMO of the matrix material and of the LUMO of the doping agent are decisive for the doping effect.
Electronic components having doped layers include OLEDS and solar cells, among others. OLEDs are known for example from U.S. Pat. No. 7,355,197 or US2009/0051271. Solar cells are known for example from US2007/0090371 and US2009/0235971.
The present invention has the task of overcoming the disadvantages of the prior art.